Review

Question: In patients with ischemic heart disease, is it useful and safe to transfuse packed red blood cells (PRBC)? Reviews literature on anemia and cardiovascular disease, transfusion and outcomes in ischemic heart disease and in surgical patients with heart disease. Includes the following 2 studies:

Rao SV et al. Relationship of blood transfusion and clinical outcomes in patients with acute coronary syndromes. JAMA. 2004 Oct 6;292(13):1555-62.CONCLUSIONS: Blood transfusion in the setting of acute coronary syndromes is associated with higher mortality, and this relationship persists after adjustment for other predictive factors and timing of events. Limitation of study is the post hoc subgroup analysis of the clinical trials data. A randomized trial of transfusion strategies is warranted.OBJECTIVE: To study the association between blood transfusion and mortality among patients with acute coronary syndromes who develop bleeding, anemia, or both while in hospitalDESIGN: Analyzed 24,112 participants in 3 trials of patients with acute coronary syndromes. Thirty day mortality and occurrence of MI were analyzed by transfusion statusRESULTS: Of the patients included, 2401 (10.0%) underwent at least 1 blood transfusion. Patients who underwent transfusion were older and had more comorbid illness at presentation and also had a significantly higher unadjusted rate of 30-day death. However, when adjusted for those factors, transfusion was associated with an increased risk for 30-day mortality (adjusted hazard ratio [HR], 3.94; 95% confidence interval [CI], 3.26-4.75).

Hébert PC , et al. Is a low transfusion threshold safe in critically ill patients with cardiovascular diseases? Crit Care Med. 2001 Feb;29(2):227-34.CONCLUSION: A restrictive red blood cell transfusion strategy generally appears to be safe in most critically ill patients with cardiovascular disease, with the possible exception of patients with acute myocardial infarcts and unstable angina.OBJECTIVE: To compare a restrictive red blood cell transfusion strategy with a more liberal strategy in critically ill patients with cardiovascular disease.DESIGN: Subgroup analysis of 357 critically ill patients with cardiovascular diseases from the Transfusion Requirements in Critical Care RCT who had a hemoglobin concentration of <90 g/L within 72 hrs of admission to the intensive care unit.INTERVENTIONS: Patients were randomized to a restrictive strategy to receive allogeneic red blood cell transfusions at a hemoglobin concentration of 70 g/L (and maintained between 70 and 90 g/L) or a liberal strategy to receive red blood cells at 100 g/L (and maintained between 100 and 120 g/L).RESULTS: Baseline characteristics: comparable for 2 groups except for use of cardiac and anesthetic drugs
Average hemoglobin and red blood cell units transfused was significantly different for the 2 groups
In the 257 patients with severe ischemic heart disease, there were no statistically significant differences in all survival measures, but this is the only subgroup where the restrictive group had lower but nonsignificant absolute survival rates compared with the patients in the liberal group.
Figure 3 compares 30-day survival in the patients in the restrictive transfusion group to those in the liberal transfusion group